Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
A typical calibration method performs correction of input-output characteristics, what is called a gamma correction, caused by a secular change or similar cause in an image forming apparatus such as a printer-only machine and a Multifunction Peripheral (MFP). The typical calibration method corrects input-output characteristics such that a color value of an output color becomes a target color value, by measuring a current output color using a scanner attached to an MFP or a print density sensor inside an image forming apparatus.